Current reclining chair designs often do not effectively match movement of a user with movement of the chair parts. For example, some chairs feature a reclining seat back coupled with a stationary seat, which does not permit the user's spine to conform to a natural position when reclining. As a user shifts a chair from an upright to a reclined position, a user's spine undergoes increased curvature, particularly in the lumbar region, which is often not addressed by chair backs which maintain the same shape throughout reclination. Therefore, there is a need in the art for an improved chair back design.